nCTEQ PDFs at the LHC: Vector boson production in heavy ion collisions

TL;DR

This paper investigates how LHC W/Z production data in heavy ion collisions can refine nuclear and proton PDFs, especially the strange quark distribution, by utilizing an improved nCTEQ++ framework for analysis.

Contribution

It introduces a new modular C++ implementation of the nCTEQ code that facilitates integration of various tools and performs preliminary fits with LHC heavy ion data.

Findings

LHC W/Z data impacts flavor differentiation in PDFs.

Nuclear corrections influence proton PDF determination.

Preliminary fits show potential for improved strange quark PDF constraints.

Abstract

Extraction of the strange quark PDF is a long-standing puzzle. We use the nCTEQ nPDFs with uncertainties to study the impact of the LHC W/Z production data on both the flavor differentiation and nuclear corrections; this complements the information from neutrino-DIS data. As the proton flavor determination is dependent on nuclear corrections (from heavy target DIS, for example), LHC heavy ion measurements can also help improve proton PDFs. We introduce a new implementation of the nCTEQ code (nCTEQ++) based on C++ which has a modular strucure and enables us to easily integrate programs such as HOPPET, APPLgrid, and MCFM. Using ApplGrids generated from MCFM, we use nCTEQ++ to perform a preliminary fit including the pPb LHC W/Z vector boson data.